in this study an innovatively designed tractor-mounted, ground-wheel driven, triple unit, row crop precision planter capable of planting three rows of garlic (allium sativum l.) cloves on each raised bed was designed, fabricated and tested. the major components of this planter include; chassis and transport wheels, lister-bedder unit, seed hopper, seed metering drum, sweeper, knocker, seed tube...

Irrigation water is limiting for crop production in arid and semi-arid areas. Furthermore, excess nitrogen (N) application is a source of groundwater contamination. Partial root drying irrigation (PRD) can be used as water saving technique and a controlling measure of groundwater N contamination. The objectives of this investigation were to evaluate the effect of ordinary furrow irrigation (OFI...

this research was carried out to evaluate the effects of irrigation methods and n fertilizer rates on the quantity and quality of sugar beet in ekbatan research station during 2001 and 2002. experiment was performed in split-plot with 3 replications and 15 treatments. treatments included 3 irrigation systems: sprinkler (solid set)، furrow (hydroflum) and drip (tape: 508-20-500) in main plots an...

During cytokinesis, a specialized set of proteins is recruited to the equatorial region between spindle poles by microtubules and actin filaments, enabling furrow assembly and ingression before cell division. We investigate the mechanisms underlying regional specialization of the cytoskeleton in HeLa cells undergoing drug-synchronized monopolar cytokinesis. After forced mitotic exit, the cytosk...

The initial steps of pattern formation in the developing Drosophila eye involve the coordination of cell cycles, changes in cell shape, and the specification of the R8 photoreceptor cell. These events begin several cell rows ahead of the morphogenetic furrow and are positively regulated by secreted signaling proteins and the proneural HLH transcription factor atonal (ato). Two HLH regulatory pr...

During anaphase, distinct populations of microtubules (MTs) form by either centrosome-dependent or augmin-dependent nucleation. It remains largely unknown whether these different MT populations contribute distinct functions to cytokinesis. Here we show that augmin-dependent MTs are required for the progression of both furrow ingression and abscission. Augmin depletion reduced the accumulation o...

Experiments on model systems have revealed that cytokinesis in cells with contractile rings (amoebas, fungi, and animals) depends on shared molecular mechanisms in spite of some differences that emerged during a billion years of divergent evolution. Understanding these fundamental mechanisms depends on identifying the participating proteins and characterizing the mechanisms that position the fu...

Cleavage furrow formation in animal cells results from a local increase in cortical contractility. During anaphase, the spindle contains, in addition to astral arrays of microtubules, a set of bundled microtubules known as the central spindle. Each of these populations of microtubules, the astral arrays and the central spindle bundles, is sufficient to direct cleavage furrow formation, yet in w...

Many of the same genes needed for proper eye and limb development in vertebrates, such as hairy, hedgehog, patched and cyclic AMP-dependent protein kinase A, are responsible for patterning Drosophila imaginal discs, the tissues that will give rise to the adult cuticle structures. This is well demonstrated in the control of morphogenetic furrow movement and differentiation in the eye imaginal di...